Most motorized vehicles currently use incandescent or high-intensity discharge sealed-beam headlamps and headlamp assemblies. The embodiments of the subject invention are designed to retrofit the current incandescent sealed-beam headlamps and headlamp assemblies. For example, many heavy-duty vehicles use four (4) inch by six (6) inch, rectangular, sealed-beam headlamps in a quad lamp assembly. In one embodiment of the present invention, four (4) inch by six (6) inch, rectangular, sealed-beam low beam and high beam headlamps, that use light emitting diodes as a light source, form a quad lamp assembly designed to retrofit the incandescent four (4) inch by six (6) inch quad packages. By way of further example, other vehicles use seven (7) inch round, sealed-beam headlamps in a dual lamp assembly. Therefore, in an alternate embodiment of the invention, seven (7) inch round, sealed-beam combined low/high beam headlamps, that use light emitting diodes as a light source, form a two-lamp assembly designed to retrofit the incandescent, seven (7) inch round packages.
The embodiments of the subject invention that are disclosed herein are designed to satisfy the Society of Automotive Engineers (SAE) Standard J1383 for high beam and low beam vehicular headlamps. SAE Standard J1383 specifies certain photometric requirements, including luminous intensity requirements, for vehicular lamps functioning as headlamps.
The Department of Transportation (DOT), in its Federal Motor Vehicle Safety Standards, 49 C.F.R. §571.108 (2000), (“FMVSS 108”) regulates all lamps, reflective devices, and associated equipment. FMVSS 108 can be found at www.nhtsa.dot.gov and is hereby incorporated by reference in its entirety. DOT Standard 1383 (part of FMVSS108) adopts the Society of Automotive Engineers (SAE) Standard J1383 (December 1996) for motor vehicle headlamps.
SAE Standard J1383 defines a headlamp as a “lighting device providing an upper and/or lower beam designed to provide illumination forward of the vehicle.” SAE Standard J1383 further defines a sealed beam headlamp assembly as “a headlamp assembly which includes one or more sealed beam headlamps.” A low beam is a “beam intended to illuminate the road ahead of a vehicle when meeting or following another vehicle.” A high beam is a “beam intended primarily for distant illumination for use when not meeting or following other vehicles.” SAE Standard J1383 also requires that the color of the emanating light produced by a headlamp shall be white as defined in SAE Standard J578.
SAE Standard J1383 also specifies certain requirements for vehicular lamps functioning as headlamps, including minimum and/or maximum luminous intensity requirements. According to the aforementioned standards, a minimum and/or maximum luminous intensity must exist at various points in the illumination zone to be in compliance. These specific photometric requirements for vehicular low beam and high beam headlamps, as set forth in SAE Standard J1383, are included hereinbelow.
TABLE 1PHOTOMETRIC SPECIFICATION - LOW BEAMLow BeamMinimum (cd)Maximum (cd)10 U to 90 U, 45° R to 45° L1258 L to 8 R, H to 4 U644 L to 4 R, H to 2 U1251 U to 1-½ L to L700½ U to 1-½ L to L1000½ D to 1-½ L to L30001-½ U to 1 R to R1400½ U to 1 R, 2 R, 3 R2700½ D to 1-½ R8000200001 D to 6 L7501-½ D to 2 R150001-½ D to 9 L and 9 R7502 D to 15 L and 15 R7004 D to 4 R8000
TABLE 2PHOTOMETRIC SPECIFICATION - HIGH BEAMHigh BeamMinimum (cd)Maximum (cd)2 U to V15001 U to 3 R and 3 L5000H to V2000075000H to 3 R and 3 L10000H to 6 R and 6 L3250H to 9 R and 9 L2000H to 12 R and 12 L5001-½ D to V50001-½ D to 9 R and 9 L15002-½ D to V20002-½ D to 12 R and 12 L7504 D to V12500Maximum Beam Candela(1)30000(1)The highest candela reading found in the beam pattern
SAE J578, entitled “Color Specification”, sets forth the definition for white light as applied to headlamps. The definition applies to the overall effective color of light emitted by a headlamp in any given direction and not to the color of the light from a small area of the lens. In SAE J578, the fundamental requirements for color are expressed as chromaticity coordinates according to the CIE (1931) standard colorimetric system.
Pursuant to SAE J578, the following requirements for white light shall apply when measured by the tristimulus or spectrophotometric methods, as are well known in the art.
TABLE 4WHITE LIGHT (ACHROMATIC)The color of light emitted from the headlamp shallfall within the following boundaries:x = 0.31 (blue boundary)x = 0.50 (yellow boundary)y = 0.15 + 0.64x (green boundary)y = 0.05 + 0.75x (purple boundary)y = 0.44 (green boundary)y = 0.38 (red boundary)
SAE J1383 standard and SAE J578 standard can also be found at www.sae.com and are hereby incorporated by reference in their entirety, as is FMVSS 108, 49 C.F.R. §571.108 (2000).
As mentioned above, one embodiment of the subject invention relates to a headlamp quad assembly that incorporates four (4) individual headlamps (i.e. 2 low beam lamps and 2 high beam headlamps). In this embodiment, each individual headlamp is a four (4) inch by six (6) inch, rectangular sealed-beam lamp. In an alternate embodiment, a dual headlamp assembly incorporates two (2) combined, high/low beam headlamps, wherein each individual headlamp is a seven (7) inch round sealed-beam lamp. In still another embodiment of the two-lamp assembly, each individual headlamp is a five (5) inch by seven (7) inch rectangular sealed-beam lamp. In each of the embodiments, the individual lamps forming a headlamp assembly emit white light (as defined above).